Copy Code Trigger Definition 

                CREATE trigger [dbo].[TR_PDACCOUNTSYSTEM_DEL] on [dbo].[PDACCOUNTSYSTEM]
          for delete
          as
          set nocount on
            if exists(select 1 from deleted where ID = '4B121C2C-CCE6-440D-894C-EA0DEF80D50B') 
                begin
                  raiserror('Cannot delete the default account system', 16, 1)
                  rollback
                end